(Boston) – Nutritionists have long endorsed fish as part of a heart-healthy diet, and now some studies suggest that omega-3 fatty acids found in the oil of certain fish, algae and human breast milk may also benefit the brain by lowering the risk of Alzheimer’s disease. In order to test whether docosahexaenoic acid (DHA), an omega-3 fatty acid, can impact the progression of Alzheimer’s disease, researchers at Boston University and Brigham and Women’s Hospital supported by the National Institute on Aging (NIA), part of the National Institutes of Health, will evaluate DHA in a clinical trial, the gold standard for medical research.

The local effort is part of a nationwide consortium of leading Alzheimer’s disease researchers supported by NIA and coordinated by the University of California, San Diego. The trial will take place at 51 sites across the United States. It seeks 400 participants age 50 and older with mild to moderate Alzheimer’s disease. Joseph Quinn, M.D., associate professor of neurology at Oregon Health and Science University, is directing the national study. Gad Marshall, M.D. at Brigham and Women’s Hospital and Anil Nair, M.D. at Boston University will conduct the study locally.

Researchers will primarily evaluate whether taking DHA over many months slows the progression of both cognitive and functional decline in people with mild to moderate Alzheimer’s. During the 18-month clinical trial, investigators will measure the progress of the disease using standard tests for functional and cognitive change.

“Evidence to date in various research studies that have examined the effect of omega-3 fatty acids on Alzheimer’s disease merits further evaluation in a rigorous clinical trial,” says Marshall of Brigham and Women’s Hospital. “Our hope is that we may find out that DHA plays a role in slowing the progression of this destructive disease.”

In recent European studies and the Framingham Heart Study, scientists reported that people with the highest blood levels of DHA were about half as likely to develop dementia as those with lower levels.

“Study volunteers will be critical to helping us find out if DHA can make an impact on the disease process,” says Nair at Boston University.

For the clinical trial the Martek Biosciences Corporation of Columbia, Md., will donate a pure form of DHA made from algae devoid of fish-related contaminants. Participants will receive either two grams of DHA per day or an inactive placebo pill. About 60 percent of participants will receive DHA, and 40 percent will get the placebo. Doctors and nurses at the 52 research clinic sites will monitor the participants in regular visits throughout the trial. To ensure unbiased results, neither the researchers conducting the trial nor the participants will know who is getting DHA and who is receiving the placebo.

In addition to monitoring disease progression through cognitive tests, researchers will also evaluate whether taking DHA supplements has a positive effect on physical and biological markers of Alzheimer’s, such as brain atrophy and proteins in blood and spinal fluid.

To learn how to participate in the study, call 617-414-1078 at Boston University, 617-732-8085 at Brigham and Women’s Hospital, the NIA’s Alzheimer’s Disease Education and Referral Center at 1-800-438-4380 or email adear@nia.nih.gov.

The NIA leads the federal effort that supports and conducts research on aging and the medical, social and behavioral issues of older people, including Alzheimer’s disease and age-related cognitive decline. For more information visit the NIA’s Alzheimer’s Disease Education and Referral Center at http://www.nia.nih.gov/alzheimers, or call 1-800-438-4380. For general information on research and aging, go to www.nia.nih.gov and for information about NIH and its programs, visit http://www.nih.gov.